The earliest change that we can see in the retina are scattered red dots called microaneurysms. These microaneurysms tell us that the retinal blood vessels are damaged by diabetes. These changes require regular monitoring.

2. Diabetic maculopathy

Diabetic maculopathy can result when fluid seeps out of these microaneurysms or blood vessels. It causes damage to the part of the eye, which provides central vision (macula).

3. Proliferative diabetic retinopathy

This is an advanced stage of retinopathy, where weak new blood vessels are formed. This can often lead to scarring of the retina and can cause retinal detachment.

Sight loss in diabetic retinopathy is a result of changes in the retina caused by high blood sugar. Over time, it damages the blood vessels that provide nutrition and oxygen to the retina.

The damage makes the blood vessel walls leak blood and fluid in the centre of the retina (macular oedema). Eventually, unhealthy new blood vessels grow and can bleed. They can cause scarring of the retina or pull the retina (retinal detachment), causing severe sight loss.

People of Afro-Caribbean or South Asian heritage are about twice as likely to develop sight-threatening diabetic retinopathy as white Europeans.

Within 20 years of diagnosis nearly everyone with type 1 diabetes and two-thirds of people with type 2 diabetes will have some degree of diabetic retinopathy. Its effect on sight can vary widely.

Diabetic retinopathy may progress without any symptoms. Symptoms can include the appearance of “floating” spots, blurred vision, double vision and eye pain. However, symptoms don’t tend to be noticed until the later stages of diabetic retinopathy. So it’s important to screen for this condition regularly to ensure timely treatment.

Keeping good control of diabetes lowers the risk of developing diabetic retinopathy. This includes controlling blood sugar level, cholesterol and blood pressure. Decreased vision due to diabetic maculopathy is best treated with regular anti-VEGF injections into the eye until the retina stabilises.

In the early stages, diabetic retinopathy needs regular monitoring rather than treatment. If it gets worse, it can be treated with laser surgery, which treats cases of proliferative diabetic retinopathy, by treating the growth of the new weak and bleeding blood vessels at the retina. Eye injections with anti-VEGF medication have been found to be effective in proliferative diabetic retinopathy. Surgery may be done in severe cases to clear blood, repair detached retinas and remove scar tissue.

Diabetic retinopathy research aims to prevent sight loss. We are trying to understand more about how blood vessels become leaky in diabetes. We also want to know more about any changes in the retina that may come before the changes to blood vessels. Several potential therapies are being developed to prevent and treat the complications caused by diabetic retinopathy.

Kevin Bradley from Leeds was diagnosed with type 1 diabetes when he was 12.

Kevin was diagnosed with retinopathy in 2015. Within 20 years, 95% of diabetics will have some sort of retinopathy issues, so he's coming up to that 20-year mark.

“I've previously had a permanent blind spot in my left eye, at about 10 o’clock, just off-centre. After two weeks it was still there and I thought, ‘That’s it - it’s going to be there forever’, but a week later it had gone. They come and go. Colour-wise, a blind spot is grey. You know when you close your eyes, and look through your eyelids? That’s the kind of colour it is."

“It could get very bad in the future, but there’s nothing I can do about it, apart from controlling my diabetes as best I can. I can only get on with it."

You could play an important part in eye research by being a participant in clinical research study that may benefit many people. You could even help shape clinical research by becoming more actively involved and having a say. Patients, carer, or anyone with an interest can help.

What are clinical trials

Clinical trials are research studies that find out if a medical strategy, treatment, or device is safe and effective for humans. They are a key research tool for improving medical knowledge and patient care. The people who carry out research are mostly the same doctors and healthcare professionals who treat people. Their aim is to find better ways of treating patients and keeping people healthy.

Taking part

Here are some ways to find out about research projects and clinical trials that you can get involved in.

UK Clinical Trials Gateway

The UK Clinical Trials Gateway run by the National Institute for Health Research (NIHR) provides easy to understand information about clinical research trials running in the UK, and gives to a large range of information about these trials. It is designed to enable patients and clinicians to locate and contact trials of interest. Visit their website and select the eye condition that you are interested in.

NIHR Clinical Research Network Portfolio

The NIHR Clinical Research Network Portfolio is a database of high-quality clinical research studies in England, Northern Ireland, Scotland and Wales. Within this the Ophthalmology Specialty Group supports a national portfolio of research studies in ophthalmology and the vision sciences. See their website for details.

If you wish to join a trial it is always best to discuss this with your doctor or clinical team first.

Last update November 2017 Approved by Dr Sobha Sivaprasad, Moorfields Eye Hospital and King’s College Hospital